This free app guides users through the Norwegian 4x4 interval training protocol to improve cardio and VO2 Max. It supports various cardio activities and allows for customization of interval durations and repetitions.



250+ iOS apps curated and reviewed
Out of 250+ norwegian 4x4 timer apps on iOS, 18 are free and the rest sit in the paid tier. This page sorts them so you can compare both sides before you commit.
| # | App | Price | Rating | Ads | In-App Purchases | Updated | |
|---|---|---|---|---|---|---|---|
| 1 | Free | 5.0★ (1) | No | No | Sep 2026 | ||
| 2 | Free | — | Yes | Yes | Sep 2026 | ||
| 3 | Free | 5.0★ (3) | No | Yes | Sep 2026 | ||
| 4 | Free | 4.8★ (61) | No | Yes | Sep 2026 | ||
| 5 | Free | 5.0★ (1) | No | No | May 2026 | ||
| 6 | Free | — | No | No | Jun 2026 | ||
| 7 | $0.99 | 1.4★ (5) | No | No | Sep 2026 | ||
| 8 | $0.99 | — | No | No | Aug 2026 |



This free app guides users through the Norwegian 4x4 interval training protocol to improve cardio and VO2 Max. It supports various cardio activities and allows for customization of interval durations and repetitions.











This app guides you through a structured interval workout, calculating your target heart rate zones and providing real-time coaching. It features a simple warm-up, four intense 4-minute intervals with recovery periods, and a cool-down, all managed by an integrated timer. Track your progress and sync data with Apple Health.